Recent studies from Asia have reported a wide variation in the incidence of deep vein thrombosis (DVT), ranging from 5% to 50% in patients undergoing major abdominal surgery. However, data specific to the Nepalese population remains unavailable. This study aims to evaluate current thromboprophylaxis practices and determine the incidence of DVT in Nepalese adults undergoing gastrointestinal and hepatobiliary surgery.

Inclusion Criteria:

• Adults aged >18 years
• Underwent major gastrointestinal or hepatobiliary surgery
• Surgery performed under general anesthesia
• Major surgery defined as any operative intervention in the abdominal or hepatobiliary region requiring general anesthesia

Exclusion Criteria:

• History of VTE within 3 months before surgery
• Known hypercoagulable state or congenital thrombophilia
• Diagnosis of atrial fibrillation
• Undergoing systemic cancer chemotherapy or radiotherapy within the past 15 days
• Pregnant or lactating women
• Missing information in clinical records
• Non-operated patients or those receiving conservative management
• Patients undergoing liver transplantation

The study population consisted of adult patients aged >18 years who underwent major gastrointestinal or hepatobiliary surgery under general anesthesia at a tertiary referral center in Nepal. Patients were identified retrospectively through departmental audit records from the Department of Surgical Gastroenterology between October 2021 and April 2024. Major surgery was defined as any operative intervention involving the abdominal or hepatobiliary region requiring general anesthesia. Surgical procedures were categorized by organ system into upper gastrointestinal, hepatopancreatobiliary (HPB), colorectal, and other (e.g., small intestine, retroperitoneum, abdominal wall). Patients with a recent history of venous thromboembolism (VTE), known hypercoagulable conditions, atrial fibrillation, ongoing cancer therapy, pregnancy, or incomplete clinical data were excluded from the study. Data collected included demographic, clinical, intraoperative, and postoperative variables relevant to thromb

De-identified individual participant data (IPD) related to demographic characteristics, surgical details, thromboprophylaxis use, and DVT outcomes will be shared. This includes preoperative, intraoperative, and postoperative variables as collected in the study.

The IPD and supporting documents will be available beginning six months after publication of the study results and will remain available for up to five years thereafter.

Access will be granted to qualified researchers and institutions conducting ethically approved research. Requests must include a brief study proposal and intended use. Data will be made available through a secure data-sharing platform upon signing a data use agreement.